Radical prostatectomy for prostate cancer: the perineal approach increases the risk of surgically induced positive margins and capsular incisions.

PURPOSE

We compare the incidence of positive surgical margins in patients who underwent perineal or retropubic radical prostatectomy for clinically localized (stage T1, T2) prostate cancer.

MATERIALS AND METHODS

In this retrospective, nonrandomized study we reexamined the specimens of 94 consecutive patients who underwent radical perineal (48) or retropubic (46) prostatectomy for clinically localized prostate cancer (stage T1, T2) and with pathological stage pT2 (intracapsular), pT3A (established extracapsular extension without positive margins) or pT3B (extracapsular extension with positive margins) without lymph node involvement (N0). We assessed the presence or absence of extracapsular cancer with or without positive margins, incisions of the prostatic capsule exposing cancer (surgically induced positive margins) or benign glandular tissue. Patients were followed for 3 to 66 months (mean 25) using an ultrasensitive prostate specific antigen assay with a lower detection limit of less than 0.05 ng./ml.

RESULTS

The overall incidence of positive margins in cancer tissue was 56% in the perineal and 61% in the retropubic group, and biochemical failure-free survival was 67% each. However, surgically induced positive margins in patients with organ confined disease were more frequent in the perineal than retropubic group (43 versus 29%, p < 0.05) and associated with a 37% risk of biochemical failure (prostate specific antigen greater than 0.1 ng./ml.) at mean followup. In addition, capsular incisions exposing benign tissue were more frequent in the perineal than retropubic group (90 versus 37%, p < 0.05) irrespective of pathological stage.

CONCLUSIONS

Although overall positive margins and biochemical failure rates are similar or identical for the perineal and retropubic approaches for organ confined prostate cancer, the perineal approach is associated with a significantly higher risk of capsular incisions and surgically induced positive margins and, thus, a higher risk of biochemical failure.